In the past, outdoorspersons had a number of techniques for providing potable water. One technique was to use waterproof canvas or plastic weighed down with rocks and placed close to the ground to condense low lying ground vapor, or dew, into a container drop by drop. Another technique was the use of a solar powered still to distill pure water from contaminated water. Both these methods were time consuming and inconvenient.
Another approach was to use chemical water purification tablets which worked by chemically generating chlorine or iodine. Again, these were time consuming and often added an unpleasant taste to the water. Further, the tablets, when used at normal or acceptable concentrations, were ineffective against protozoa.
With the increasing popularity of camping and hiking in remote wilderness areas, a better system of obtaining potable water was required. This led to the development of the pump water filtration system. In this system, a pump was connected to a filter with one tube being inserted in the potentially contaminated water and a second tube inserted into a container. By hand pumping the pump, contaminated fluid was drawn into the pump during an intake stroke and then expelled through the filter media, generally a cylindrical ceramic filter, to the second tube and to the container. These types of devices provide high volumes of water and are highly efficient in filtering action; however, because of the mechanical complexity of these types of systems, they are expensive and generally not within the reach of the casual outdoors-person. Also, these devices are intended for use over a long period of time and risk bacterial growth through the filter material from the contaminated side to the filtered side. Further, for true wilderness campers and hikers or mountaineers, they had the disadvantage of being relatively bulky for carrying in backpacks where space is at a premium.
Thus, there has been a long sought need for a water filtration system which would be fully portable in taking up a minimum volume, weighing as little as possible, and being inexpensive.
Further, a low energy input system was desired which would not require strenuous pumping or be dependent upon weather being clear enough for solar energy to do the job.